Abstract: An optically isolated TO-can including a header with electrical connections, a laser diode mounted on the header, and a lens cap positioned over the laser diode so as to enclose and hermetically seal the laser diode. The optically isolated TO-can includes an optical isolator positioned in the TO-can adjacent the laser diode and in the light path of light generated by the laser diode.

Abstract: An optical element includes at least with a Faraday rotator of which both light-transmission surfaces are bonded through a bonding layer to light-transmission surfaces of polarization glasses which are orientationally dispersed with anisotropically-shaped particles at their surfaces. Each of the polarization glasses includes the orientationally dispersed anisotropically-shaped particles only at one surface opposite to the bonding surface. A relation t?30 ?m is satisfied, wherein t denotes a distance between one of the bonding surfaces of the Faraday rotator and that surface of the polarization glass on the one of the bonding surfaces of the Faraday rotator which is disposed with the particles. As a result, high isolation (25 dB or higher) can be maintained, even if a polarization glass which includes a thin layer with orientationally dispersed anisotropically-shaped particles is used.

Abstract: The present invention is a garnet-type single crystal represented by the following general formula: (Tb3-xScx) (Sc2-yAly)Al3O12-z ??(1) (wherein, x satisfies 0<x<0.1).

Abstract: An integrated optical device functioning as optical isolator, shutter, variable optical attenuator, and modulator is disclosed. The device employs a Pockels cell for dynamically rotating with nanosecond speed the polarization state of incident light for attenuation and modulation. The invention provides a compact, high performance and reliable device without moving parts for use in laser systems and particularly in fiber optic telecommunication system.

Abstract: A thermally compensated optical device includes in an optical path an input linear polarizer for transmitting linearly polarized light from a received light beam at a design wavelength. A composite reciprocal rotator includes a first reciprocal material and at least a second reciprocal material provides a reciprocal rotation having a temperature coefficient for reciprocal rotation (tempcorr). At least one Faraday rotator provides a non-reciprocal rotation having a temperature coefficient for non-reciprocal rotation (tempconr). An output linear polarizer transmits forward light received after transmission by the Faraday rotator. At a design temperature, the tempcorr and tempconr have opposite signs and can have magnitudes that match within 50%.

Abstract: Provided is a polarization independent optical isolator including: wedge-shaped birefringent crystal plates each made of a LiNbO3 single crystal; a Faraday rotator 3 made of a magnetic garnet single crystal; and sapphire single crystal plates 2 and 4 bonded to light transmitting surfaces of the Faraday rotator, respectively. A light transmitting surface of each of the sapphire single crystal plates is formed in such a manner as to be offset from the c-plane of the sapphire single crystal plate. An incident angle ?a of imaginary light 300 on each of the sapphire single crystal plates, and an offset angles ?off of the light transmitting surface from the c-plane of each sapphire single crystal plates are set within predetermined ranges, the imaginary light 300 being represented by a bisector of an angle formed by optical axes of the ordinary ray and the extraordinary ray.

Abstract: The present invention provides a garnet single crystal comprising a terbium aluminum garnet single crystal, wherein a portion of the aluminum is substituted with scandium, and a portion of at least one of the aluminum and terbium is substituted with at least one type selected from the group consisting of thulium, ytterbium and yttrium.

Abstract: An integrated optical device functioning as optical isolator, shutter, variable optical attenuator, and modulator is disclosed. The device employs a Pockels cell for dynamically rotating with nanosecond speed the polarization state of incident light for attenuation and modulation. The invention provides a compact, high performance and reliable device without moving parts for use in laser systems and particularly in fiber optic telecommunication system.

Abstract: The present application discloses various implementations of a laser scanning module. In one implementation, such a laser scanning module comprising an optical isolator including first and second linear polarizers, a collimating optics configured to receive light produced by a laser light source and to pass a substantially collimated light beam to the first linear polarizer, and a scanning unit situated to receive light passed by the second linear polarizer. The first linear polarizer is separated from the collimating optics by a first distance less than a second distance separating the second linear polarizer from the scanning unit.

Abstract: A compact narrow band imaging system includes a vapor cell having a gas that receives and transmits light in accordance with the Faraday effect. A magnetic source is provided for applying a magnetic field to the vapor cell. Crossed polarizers are disposed before and after the vapor cell creating a Faraday optical filter. The only light that passes through the filter is light within a narrow band near the absorption peaks of the vapor. Other optical elements of the imaging system including filters, image detectors, electron multipliers, signal digitizers, and heat filters are co-located within the imaging system's common thermal isolation container to provide improved performance. The compact system is suitable for wide area surveillance, including daylight surveillance for combustion sources such as forest fires and missile exhaust.

Abstract: An optical module is provided that includes a Faraday rotator having a Verdet constant at a wavelength of 1.06 ?m of at least 0.27 min/(Oe·cm), a first hollow magnet disposed on the outer periphery of the Faraday rotator, and second and third hollow magnet units disposed so as to sandwich the first hollow magnet on the optical axis. The second and third hollow magnet units include 2 or more magnets equally divided in a direction of 90 degrees relative to the optical axis. A magnetic flux density B (Oe) applied to the Faraday rotator is in the range of 0.5×104?B?1.5×104. The Faraday rotator is disposed on a sample length L (cm) in the range of 0.70?L?1.10, and has an external diameter D (cm) in the range of 0.20?D?0.60.

Abstract: An opto-isolator including a Faraday rotator comprised of a crystal cylinder formed into a cylinder using a crystal that rotates polarized light; an enclosing tube surrounding the crystal cylinder; two cooling tubes each sized and positioned to allow both ends of the outer peripheral surface of the crystal cylinder to be inscribed within the cooling tubes and both end sections of an inner peripheral surface of the enclosing tube to be circumscribed around the cooling tubes; passages formed within the cooling tubes; a cooling medium circulating through a space formed among the crystal cylinder, the enclosing tube, and the two cooling tubes, and the passages; and a magnet disposed in an outer periphery of the enclosing tube. The opto-isolator further includes two polarizers respectively disposed on the optical path of light entering the Faraday rotator and an optical path of the light exiting the Faraday rotator.

Abstract: The present invention provides a single crystal for an optical isolator having a Faraday rotation angle exceeding that of TGG single crystal in a wavelength region of 1064 nm or longer or in a wavelength region of shorter than 1064 nm, and is capable of realizing enlargement of crystal size, a production process thereof, an optical isolator, and an optical processor that uses the optical isolator. The single crystal according to the present invention is composed of a terbium aluminum garnet single crystal, and mainly a portion of the aluminum is replaced with lutetium.

Abstract: The present invention relates to an optical insulator for high power optical radiation. The arrangement of the optical insulator comprises a Faraday rotator, comprising one or more Faraday media (4) and a magnet assembly (1) that allows for the receiving of multiple Faraday media (4). A polarizer assembly is arranged both in front of and behind the Faraday media (4). The magnet assembly (1) is formed by magnets (2) shaped in such a way that at least the outer-lying magnets are parallelepiped. The free aperture (3) is surrounded by three magnetic levels (12, 12?, 12?).

Abstract: The near-field extinction ratio of a polarizing glass is increased. A polarizing glass contains anisotropically shaped metal particles oriented and dispersed in a glass substrate, which contains 0.40-0.85 wt % Cl relative to the entire glass substrate. The Vickers hardness ranges from 360 to 420, the Knoop hardness number ranges from 400 to 495, or the glass substrate contains at least one component selected from the group consisting of Y2O3, La2O3, V2O3, Ta2O3, WO3, and Nb2O5. The content of each of the selected components ranges from 0.05-4 mole percent, and if a plurality of the components are selected, the total content of the components is 6 mole percent or less.

Abstract: An optical isolator 1 element comprises a Faraday rotator 11 that rotates a polarization plane of light; a first polarizer of optical absorption type 12 arranged on one surface side of the Faraday rotator 11, the first polarizer 12 having a layer in which metal particles are distributed; and a second polarizer of optical absorption type 13 arranged on another surface side of the Faraday rotator 11, the second polarizer 13 having a metal particle layer in which metal particles are distributed in a density higher than the density of metal particles distributed in the metal particle layer of the first polarizer 12. The optical isolator 1 makes it possible to reduce a deterioration of isolation caused by occurring a reflected light reflected between the second polarizer 13 and the first polarizer 12.

Abstract: A method to easily manufacture a nanosized EuSe crystal which has been conventionally difficult to be manufactured. Heating an Eu(III) complex whose general formula is represented by the following formula generates an EuSe crystal having a particle size corresponding to the heating condition. Alternatively, the mixture composed of Eu(III) complex, a counter cation, and a solvent may be heated. The particle size of the nanosized EuSe crystals can be manipulated by the heating condition, thus the absorption wavelength of the EuSe crystals can be easily controlled. In addition, it is easy to create a magnetooptic-responsive plastic using the high dispersibility of the EuSe crystals, thus it can be immediately applied to an optical isolator or other devices.

Abstract: A Faraday rotator of an opto-isolator in a laser processing apparatus includes a crystal cylinder that causes the Faraday effect, an enclosing tube, cooling tubes, and a magnet. The enclosing tube encases the crystal cylinder. The cooling tubes are sandwiched between the crystal cylinder and the enclosing tube at both ends of the crystal cylinder. The cooling tubes have passages through which a coolant flows. The coolant circulates through a space between the crystal cylinder and the enclosing tube, and the passages, thereby cooling the crystal cylinder.

Abstract: The near-field extinction ratio of a polarizing glass is increased. A polarizing glass contains anisotropically shaped metal particles oriented and dispersed in a glass substrate, which contains 0.40-0.85 wt % Cl relative to the entire glass substrate. The Vickers hardness ranges from 360 to 420, the Knoop hardness number ranges from 400 to 495, or the glass substrate contains at least one component selected from the group consisting of Y2O3, La2O3, V2O3, Ta2O3, WO3, and Nb2O5. The content of each of the selected components ranges from 0.05-4 mole percent, and if a plurality of the components are selected, the total content of the components is 6 mole percent or less.

Abstract: A magnetic circuit for a Faraday rotator capable of suppressing generation of irreversible demagnetization is provided. This magnetic circuit (100, 200, 300, 400, 500, 600, 700, 800, 900) for a Faraday rotator includes a first magnet (2, 202, 302, 702, 802), a second magnet (3, 203, 303, 703, 803) and a third magnet (4, 304, 604, 704, 804, 904), and a first high coercive force region (4b, 304b, 604b, 704b, 904b) is provided in the vicinity of at least the inner peripheral surface of a third through-hole (4a, 304a, 604a, 704a, 804a, 904a) of the third magnet.

Abstract: In an in-line optical isolator, a first polarization separation element 91, a Faraday rotator 6 made of a BIG film, and a second polarization separation element 92 are placed in that order. The isolator further includes a first optical fiber collimator 1a being placed at the forward-beam incident side of the first polarization separation element 91 and including a collimating lens 101 and a first optical fiber 31, and a second optical fiber collimator 2a being placed at the forward-beam exit side of the second polarization separation element 92 and including a collimating lens 102 and a second optical fiber 32 connected to a fiber amplifier. Also, an edge filter 100, which transmits light emitted from the first optical fiber 31 and having a wavelength equal to an oscillation wavelength and which reflects light emitted from the first optical fiber 31 and having wavelengths shorter than this wavelength, is placed between the second optical fiber collimator 2a and the second polarization separation element 92.

Abstract: An optical element transmits incident light having a particular polarization direction mainly by 0-order transmission and diffracts incident light having a perpendicular polarization direction. The optical element includes a periodic structure having a period equal to or greater than the wavelength of the incident light. The periodic structure includes first and second subwavelength concave-convex structures formed perpendicularly adjacent to each other in each period of the periodic structure. The first and the second subwavelength concave-convex structures have a period less than the wavelength of the incident light. A filling factor and a groove depth of the first and the second subwavelength concave-convex structures are determined such that they have the same effective refraction index with respect to the incident light having the particular polarization direction and a phase difference ? with respect to the incident light having the particular polarization direction.

Abstract: An all-fiber Faraday rotator including a plurality of optical fibers doped, at unusually high concentrations of at least several tens of percent, with rare-earth oxides, an all-optical-fiber optical isolator employing a polarization-maintaining fiber-optic splitter, and a method of optically-isolating a laser source from unwanted feedback with such an optical isolator. In a case where the doping concentration exceeds 55 weight-%, the length of the Faraday rotator achieving a 45-degree rotation of the polarization vector of light guided by an optical fiber does not exceed approximately 10 cm.

Abstract: The near-field extinction ratio of a polarizing glass is increased. A polarizing glass contains anisotropically shaped metal particles oriented and dispersed in a glass substrate, which contains 0.40-0.85 wt % Cl relative to the entire glass substrate. The Vickers hardness ranges from 360 to 420, the Knoop hardness number ranges from 400 to 495, or the glass substrate contains at least one component selected from the group consisting of Y2O3, La2O3, V2O3, Ta2O3, WO3, and Nb2O5. The content of each of the selected components ranges from 0.05-4 mole percent, and if a plurality of the components are selected, the total content of the components is 6 mole percent or less.

Abstract: Various optical isolator embodiments are disclosed. Embodiments comprise a waveguide section utilizing materials that induce a propagation constant shift that is propagation-direction-dependent. Embodiments are characterized by a cutoff frequency for forward propagating waves that is different than the cutoff frequency for reverse waves; the dimensions and direction of magnetization of the waveguide can be tailored so that, in a particular embodiment, the cutoff frequency for forward propagating waves is lower than the cutoff frequency for reverse waves. A particular embodiment is constructed as a single-mode waveguide on a substrate. The cross-section of the waveguide is inhomogeneous in terms of materials. At least one part of the cross-section is a non-reciprocal magneto-optic medium, which has nonzero off-diagonal permittivity tensor components. This inhomogeneity induces a propagation constant shift, which is propagation-direction-dependent.

Abstract: An optical isolator including a Faraday rotator that has a high Faraday effect and a high transmission factor in a wavelength used is provided. An optical isolator comprises at least: a Faraday rotator; a polarizer arranged on a light incidence side of the Faraday rotator; and an analyzer arranged on a light exit side of the Faraday rotator, wherein the Faraday rotator consists of an oxide that contains an ytterbium oxide (Yb2O3) with a mass ratio of 30% or more.

Abstract: In this invention, a free space isolator is utilized to protect high performance semiconductor lasers from back reflections by stabilizing optical elements of the isolator within a glass base inside a magnetic ring.